U.S. patent application number 13/360972 was filed with the patent office on 2012-12-06 for auto-document feeder and auto-document feeding method.
This patent application is currently assigned to TOSHIBA TEC KABUSHIKI KAISHA. Invention is credited to Seiji Iino, Mitsunori Ishii, Takeshi Ito, Osamu Kitazawa, Takeshi Kojima, Shinji Miwa, Naoki Shoji, Shoichi Taniguchi, Akihito Tokutsu.
Application Number | 20120308285 13/360972 |
Document ID | / |
Family ID | 47261803 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120308285 |
Kind Code |
A1 |
Shoji; Naoki ; et
al. |
December 6, 2012 |
AUTO-DOCUMENT FEEDER AND AUTO-DOCUMENT FEEDING METHOD
Abstract
An auto-document feeder includes plural conveying sections which
have different paths to reach an image scanning section configured
to scan an image on a document from a paper feeding section and
which guide the document to the image scanning section, a scanning
conveying section configured to alternately nip the documents one
by one fed by the plural conveying sections and feed the documents
in a direction of a paper discharge section through the image
scanning section, a gate section which directs the documents to one
of the plural conveying sections, and a detecting section
configured to detect if a document is fed by the paper feeding
section.
Inventors: |
Shoji; Naoki; (Kanagawa,
JP) ; Miwa; Shinji; (Tokyo, JP) ; Taniguchi;
Shoichi; (Shizuoka, JP) ; Kitazawa; Osamu;
(Shizuoka-ken, JP) ; Tokutsu; Akihito; (Kanagawa,
JP) ; Iino; Seiji; (Kanagawa, JP) ; Ishii;
Mitsunori; (Tokyo, JP) ; Kojima; Takeshi;
(Shizuoka, JP) ; Ito; Takeshi; (Shizuoka,
JP) |
Assignee: |
TOSHIBA TEC KABUSHIKI
KAISHA
Tokyo
JP
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
47261803 |
Appl. No.: |
13/360972 |
Filed: |
January 30, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61493708 |
Jun 6, 2011 |
|
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|
Current U.S.
Class: |
399/367 |
Current CPC
Class: |
G03G 15/602 20130101;
G03G 2215/00189 20130101; G03G 2215/00358 20130101 |
Class at
Publication: |
399/367 |
International
Class: |
G03G 13/00 20060101
G03G013/00; G03G 15/00 20060101 G03G015/00 |
Claims
1. An auto-document feeder comprising: a paper feeding section
configured to feed documents one by one, from which images are read
by an image scanning section; a paper discharge section which
discharges the documents passed through the image scanning section;
plural conveying sections which have different paths to reach the
image scanning section configured to scan an image on a first side
of the document from the paper feeding section and which guide the
document from the paper feeding section to the image scanning
section; a scanning conveying section configured to alternately nip
the documents fed one by one by the plural conveying sections and
feed the documents in a direction of the paper discharge section
through the image scanning section; a gate section which directs
the documents fed by the paper feeding section to one of the plural
conveying sections; and a detecting section configured to detect if
a document is fed by the paper feeding section.
2. The feeder according to claim 1, wherein the detecting section
is a piezoelectric sensor.
3. The feeder according to claim 2, wherein the plural conveying
sections include a first conveying section and second conveying
section, and the gate section directs the document from the paper
feeding section to one of the first conveying section and second
conveying section.
4. The feeder according to claim 3, wherein the gate section
alternately directs the documents to the first conveying section or
the second conveying section.
5. The feeder according to claim 3, wherein the first conveying
section or second conveying section causes a following document to
remain idle in the conveying section while a preceding document is
scanned by the image scanning section.
6. The feeder according to claim 3, wherein the first conveying
section or second conveying section causes a point in time when a
rear end of the preceding document passes the image scanning member
and a point in time when a forward end of the following document
reaches the image scanning section to coincide with each other.
7. The feeder according to claim 3, wherein the first conveying
section has a first timing sensor which detects the document and
the second conveying section has a second timing sensor which
detects the document.
8. The feeder according to claim 7, wherein the first conveying
section or the second conveying section detects a time when the
rear end of the preceding document passes the image scanning
section by using the first timing sensor or the second timing
sensor, detects a time when the forward end of the following
document reaches the image scanning section by using the first
timing sensor or the second timing sensor, and causes the time when
the rear end of the preceding document passes the image scanning
section and the time when the forward end of the following document
reaches the image scanning section to coincide with each other.
9. The feeder according to claim 2, further comprising a second
image scanning section which scans an image on a second side of the
document, in the paper discharge section.
10. The feeder according to claim 9, wherein the image scanning
section scans the image on the first side of the document, and the
second image scanning section scans the image of the second side of
the document.
11. An auto-document feeding method, comprising: feeding documents
one by one, from which images are read, by an image scanning
section; discharging the documents passed through the image
scanning section; scanning an image on a first side of the
documents from a paper feeding section and guiding the documents
from the paper feeding section to the image scanning section using
plural conveying sections which have different paths to reach the
image scanning section; alternately nipping the documents fed one
by one by the plural conveying sections and feeding the documents
in a direction of a paper discharge section through the image
scanning section; directing the documents fed by the paper feeding
section to one of the plural conveying sections; and detecting if a
document is fed by the paper feeding section.
12. The method according to claim 11, wherein directing the
documents comprises directing the documents from the paper feeding
section to one of a first conveying section and a second conveying
section in order.
13. The method according to claim 11, wherein directing the
documents comprises alternately directing the documents to a first
conveying section or a second conveying section.
14. The method according to claim 11, further comprising causing a
following document to remain idle in the conveying section while a
preceding document is scanned by the image scanning section.
15. The method according to claim 11, further comprising causing a
point in time when a rear end of the preceding document passes the
image scanning member and a point in time when a forward end of the
following document reaches the image scanning section to coincide
with each other.
16. The method according to claim 11, further comprising scanning
an image on a second side of the document.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from U.S. Provisional Application Ser. No. 61/493,708
filed on Jun. 6, 2011, the entire contents of which are
incorporated herein by reference.
FIELD
[0002] This disclosure relates to an auto document feeding device
which conveys a document to an image scanning device used for a
copy machine, printer, or the like which facilitates high-speed
scanning.
BACKGROUND
[0003] In an image scanning device such as a scanner used for an
image forming apparatus such as a copy machine or printer, an
increase in the image scanning speed is desired. Conventionally,
there is a device in which plural document scanning conveying paths
are formed and in which a scanning sensor for scanning a face-side
image of the document and a scanning sensor for scanning a
back-side image are provided in different conveying paths, thereby
increasing the scanning speed at the time of double-side scanning
of the document images. As such an image scanning device, for
example, a device can have a first branch path through which a
document is conveyed to a first scanning position, and a second
branch path through which a document is conveyed to a second
scanning position. Moreover, for example, a device can have a
scanner device and a CIS (contact image sensor) provided on the
opposite sides of a first conveying path and simultaneously uses
the scanner device and the CIS to scan both sides of a document
conveyed on the first conveying path.
DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a configuration view schematically showing an
image scanning device according to an embodiment;
[0005] FIG. 2 is a block diagram showing a control system of an ADF
according to an embodiment;
[0006] FIG. 3 is a flowchart showing operations from turning on
power to starting supply of a document according to an
embodiment;
[0007] FIG. 4 is a flowchart showing operations to supply the
document and convey the document to an OUT conveying member
according to an embodiment;
[0008] FIG. 5 is a flowchart showing an operation to convey the
document by using OUT conveying member according to an
embodiment;
[0009] FIG. 6 is a flowchart showing operations from the start of
scanning of an image to the end of scanning; and
[0010] FIG. 7 is a flowchart showing an operation to convey a
following document by using an IN conveying member according to an
embodiment; and
[0011] FIG. 8 is a flowchart showing completion of the conveying
according to an embodiment.
DETAILED DESCRIPTION
[0012] According to an embodiment, an auto-document feeder includes
a paper feeding section configured to feed documents one by one,
from which images are read by an image scanning section; a paper
discharge section which discharges the documents that have passed
through the image scanning section; plural conveying sections which
have different paths to reach an image scanning section configured
to scan an image on a first side of the documents from the paper
feeding section and which guide the documents from the paper
feeding section to the image scanning section; a scanning conveying
section configured to alternately nip the documents one by one fed
by the plural conveying sections and feed the documents in a
direction of the paper discharge section through the image scanning
section; a gate section which divides the documents, which have
been fed by the paper feeding section, to one of the plural
conveying sections; and a detecting section configured to detect if
a document is fed by the paper feeding section.
[0013] Hereinafter, an embodiment is described. FIG. 1 shows an
image scanning device 100 according to the embodiment. The image
scanning device 100 has a scanner 110, which is an image scanning
member, and an auto document feeding device (ADF) 10 which conveys
a document G to the scanner 110. The scanner 110 has a READ
document glass 110a and a platen glass 110b of a document setting
table. The scanner 110 also has an optical mechanism 110c. The
optical mechanism 110c optically scans an image of the document G
traveling on the READ document glass 110a. Alternatively, a driving
unit, not shown, moves the optical mechanism 110c in the direction
of arrow A (see FIG. 1) along the platen grass 110b, and optically
scans the image of the document G set on the Platen glass 110b. The
scanner 110 has a photosensor, such as a CCD (charge coupled
device) 110d which photoelectrically converts an optical signal
from the optical mechanism 110c to an electric signal.
[0014] The auto document feeding device 10 has a document tray 11,
which is a document stacking member, a pickup roller 12 which takes
out the document G from the document tray 11, separation paper
supply rollers 13 which prevent double feeding of the two or more
document Gs, and registration rollers 14 which align the forward
end of document G removed and conveyed from the document tray 11.
And there is a gate piezoelectric sensor 111 downstream of the
registration rollers 14. The auto document feeding device 10 in
this embodiment has two paths as conveying paths; namely, an OUT
path 16 from the registration rollers 14 to the scanner 110, and an
IN path 17 from the registration rollers 14 to the scanner 110. The
OUT path 16, together with the document tray 11, the pickup roller
12, the separation paper supply roller 13, and the registration
rollers 14, forms an OUT conveying member 26, as a first conveying
member, for example. The IN path 17, together with the document
tray 11, the pickup roller 12, the separation paper supply rollers
13, and the registration rollers 14, forms an IN conveying member
27, as a second conveying member, for example.
[0015] The OUT path 16 has intermediate OUT rollers 18. There is
intermediate OUT path piezoelectric sensor 112 in upstream of the
intermediate OUT rollers 18. The IN path 17 has intermediate IN
rollers 28. There is an intermediate IN path piezoelectric sensor
113 upstream of the intermediate IN rollers 28. The auto document
feeding device 10 has a gate 40 which directs the document G taken
out from the document tray 11 and passed through the registration
rollers 14, to the OUT path 16 or the IN path 17.
[0016] The auto document feeding device 10 has pre-scan rollers 50
which conveys the document G that has passed through the OUT path
16 or the IN path 17 to the READ document glass 110a of the scanner
110; post-scan rollers 51 which discharge the document G from the
READ document glass 110a; pre-discharge rollers 52; paper discharge
rollers 53; and a paper discharge tray 56. There is a pre-scan
piezoelectric sensor 114 upstream of the pre-scan rollers 50. There
is a pre-discharge piezoelectric sensor 115 upstream of the
pre-discharge rollers 52. The post-scan rollers 51, the
pre-discharge rollers 52, and the paper discharge rollers 53 form a
paper discharge member. A contact image sensor (CIS) 60, which is a
second image scanning member, is provided between the post-scan
rollers 51 and the pre-discharge rollers 52. The contact image
sensor (CIS) 60 can be provided in a conveying path upstream of the
paper discharge rollers 53.
[0017] On the READ document glass 110a, an image on the face side
as a first side of the traveling document G is scanned. The CIS 60
scans an image on the backside as a second side of the traveling
document G. Thus, it is possible to scan the images on both sides
of the document G by passing the document only once in the
conveying path.
[0018] An empty sensor 70 which detects the presence or absence of
the document G is provided above the document tray 11. A
registration sensor 71 which detects arrival of the document G at
the registration rollers 14 is provided between the separation
paper supply rollers 13 and the registration rollers 14. In the OUT
path 16, a paper timing sensor OUT 72 as a first timing sensor
which detects the drive timing of the registration rollers 14 and
the intermediate OUT rollers 18 is provided. In the IN path 17, a
paper timing sensor IN 73 as a second timing sensor which detects
the drive timing of the registration rollers 14 and the
intermediate IN rollers 28 is provided. A pre-scan sensor 76 is
provided between the pre scan rollers 50 and the READ document
glass 110a. A scan sensor 77 is provided between the post-scan
rollers 51 and the pre-discharge rollers 52. A paper discharge
sensor 78 is provided between the pre-discharge rollers 52 and the
paper discharge rollers 53.
[0019] A paper supply motor 80 drive the pickup roller 12 and the
separation paper supply rollers 13 to rotate. A pickup solenoid 81
causes the pickup roller 12 to fluctuate. A registration motor (RGT
motor) 82 drives the registration rollers 14 to rotate. The gate 40
is switched by a gate solenoid 83. When the gate solenoid 83 is
turned off, the gate 40 turns in the direction of arrow x and
directs the document G to the OUT conveying member 26. When the
gate solenoid 83 is turned on, the gate 40 turns in the direction
of arrow y and directs the document G to the IN conveying member
27.
[0020] An intermediate OUT motor 84 drives the intermediate OUT
rollers 18 to rotate. An intermediate IN motor 86 drives the
intermediate IN rollers 28 to rotate. A READ motor 87 drives the
pre-scan rollers 50, the post-scan rollers 51, and the
pre-discharge rollers 52 to rotate. A paper discharge motor 88
drives the paper discharge rollers 53 to rotate.
[0021] FIG. 2 shows a block diagram of a control system 120
suitable for use with the ADF 10. The CCD 110d of the scanner 110
and the CIS 60 are connected to a body control unit 121 which
controls, for example, an entire image forming apparatus having the
image scanning device 100. The body control unit 121 controls a CPU
130 of the ADF 10 via an input-output interface 122. The empty
sensor 70, the registration sensor 71, the paper timing sensor OUT
72, the paper timing sensor IN 73, the pre-scan sensor 76, the scan
sensor 77, the paper discharge sensor 78, the gate piezoelectric
sensor 111, the intermediate OUT path piezoelectric sensor 112, the
intermediate IN path piezoelectric sensor 113, the pre-scan
piezoelectric sensor 114, and pre-discharge piezoelectric sensor
115 are connected to the input side of the CPU 130.
[0022] The pickup solenoid 81, the paper supply motor 80, the RGT
motor 82, the gate solenoid 83, the intermediate OUT motor 84, the
intermediate IN motor 86, the READ motor 87, and the paper
discharge motor 88 are connected to the output side of the CPU
130.
[0023] Here, the gate piezoelectric sensor 111, the intermediate
OUT path piezoelectric sensor 112, the intermediate IN path
piezoelectric sensor 113, the pre-scan piezoelectric sensor 114,
and the pre-discharge piezoelectric sensor 115 are explained. When
the document G is conveyed normally (without an undesirable event),
these piezoelectric sensors do not detect pressure.
[0024] When a pressure greater than a threshold value is detected
by the piezoelectric sensors, CPU 130 determines that the document
G under conveyance is bent unusually. And CPU 130 determines that a
jam exists.
[0025] When the pressure is detected for more than predetermined
time, although the pressure value detected by the piezoelectric
sensor does not exceed a threshold value, CPU 130 determines that
the document Gunder conveyance is in an abnormal state. And CPU 130
determines that a jam exists.
[0026] A process of continuously conveying documents G is described
with reference to the flowcharts of FIG. 3 to FIG. 8. After power
is turned on, it is confirmed in ACT 200 that the ADF 10 is closed.
Detection is conveyed out at all the sensors in ACT 201 to confirm
that there is no jam of documents in the ADF 10 that is closed.
When the document G is set on the document tray 11 in ACT 202, the
empty sensor 70 turns on and sends a document-on signal to the body
control unit 121. After a paper supply request signal is received
from the body control unit 121 in ACT 203, the processing goes to
ACT 206.
[0027] In ACT 206, the pickup solenoid 81 is turned on and the
paper supply motor 80 is turned on to rotate the pickup roller 12
and the separation paper supply rollers 13. As a result, supply of
the document G1 as the first sheet (the first document G1) is
started. When the registration sensor 71 turns on in ACT 207, the
document G1 is conveyed for a predetermined time and then the paper
supply motor 80 is turned off and the gate solenoid 83 is turned
off (ACT 208). The first document G1 runs into the registration
rollers 14 and/its forward end is aligned and then the first
document G1 stops. The gate 40 is set in the direction of directing
the first document G1 to the OUT conveying member 26. If the
registration sensor 71 does not turn on even after the lapse of a
predetermined time in ACT 210, it is determined that the document
G1 causes or is involved in a jam.
[0028] When the registration sensor 71 turns on in ACT 207, the
supply process of the document G2 as the second sheet (the second
document G2) starts as an interruption process, separately from and
parallel to the conveying process of the first document G1.
However, the supply process of the second document G2 remains idle
until the rear end of the first document G1 passes through the
registration sensor 71. After the registration sensor 71 changes
from on to off in ACT 300 (ACT 301), the processing goes to ACT 206
and supply of the second document G2 starts.
[0029] After a predetermined time passes in ACT 211 and the
document G1 is a sheet of an odd ordinal number (ACT 212), the RGT
motor 82 and the intermediate OUT motor 84 are turned on to rotate
the registration rollers 14 and the intermediate OUT rollers 18
(ACT 214), respectively. The intermediate OUT rollers 18 are
adjusted to the rotation speed of the registration rollers 14, and
the registration rollers 14 and the intermediate OUT rollers 18 are
rotated at a uniform velocity. The first document G1 is directed by
the gate 40 and moves to the OUT conveying member 26.
[0030] When the value which the gate piezoelectric sensor 111 and
the intermediate OUT path piezoelectric sensor 112 detected is
greater than a threshold value, it is determined that a jam exists
(ACT 215). When the value which the gate piezoelectric sensor 111
and the intermediate OUT path piezoelectric sensor 112 detected is
below a threshold value, the processing goes to ACT 216. When the
gate piezoelectric sensor 111 and the intermediate OUT path
piezoelectric sensor 112 detect pressure greater than predetermined
time, it is judged as jam (ACT216). When the gate piezoelectric
sensor 111 and the intermediate OUT path piezoelectric sensor 112
do not detect pressure more than predetermined time, the processing
goes to ACT 217.
[0031] When the paper timing sensor OUT 72 turns on in ACT 217, the
RGT motor 82 and the intermediate OUT motor 84 are driven for a
predetermined number of pulses and then stopped (ACT 219). The
first document G1 stops before the pre-scan rollers 50. If the
paper timing sensor OUT 72 does not turn on even after the lapse of
a predetermined time in ACT 218, it is judged that the document G1
causes a jam.
[0032] After a conveying request signal is received from the body
control unit 121 in ACT 220, the processing goes to ACT 221. When
the scanner 110 can scan, the body control unit 121 sends a
conveying request signal to the CPU 130. When there is a preceding
document G, and when a predetermined time passes after the forward
end of the preceding document G turns on the pre-scan sensor 76
(ACT 221), the processing goes to ACT 222.
[0033] In ACT 222, the READ motor 87 and the intermediate OUT motor
84 are turned on to rotate the intermediate OUT motor 84 are turned
on to rotate the intermediate OUT rollers 18, the pre-scan rollers
50, the post-scan rollers 51, and the pre-discharge rollers 52 at a
suitable speed according to an instruction from the body control
unit 121. The point in time when the rear end of the preceding
document G passes the pre-scan rollers 50 and the point in time
when the forward end of the first document G1 starts conveying by
the pre-scan rollers 50 are caused to coincide with each other. The
first document G1 is conveyed to the READ document glass 110a in
the state where the distance from the rear end of the preceding
document G is reduced and approaches 0 mm.
[0034] When the value which the pre-scan piezoelectric sensor 114
detected is more than a threshold value, it is determined that a
jam (ACT 230) exists. When the value which the pre-scan
piezoelectric sensor 114 detected is below a threshold value, the
processing goes to ACT 231. When the pre-scan piezoelectric sensor
114 detects pressure for more than a predetermined time, it is
determined that a jam (ACT231) exists. When the pre-scan
piezoelectric sensor 114 does not detect pressure for more than a
predetermined time, the processing goes to ACT 232.
[0035] After the first document G1 is conveyed by a predetermined
distance (ACT 232), a scan start signal is sent to the body control
unit 121. The body control unit 121 causes the scanner 110 to start
scanning an image on the face side of the document G1 (ACT
233).
[0036] In parallel, when the rear end of the first document G1
passes through the registration sensor 71 and the registration
sensor 71 changes from on to off, supply of the second document G2
is started in ACT 300. The first document G1 travels on the READ
document glass 110a. The scanner 110 scans an image of the first
document G1. The second document G2 runs into the registration
rollers 14 and its forward end is aligned. And then the second
document G2 stops.
[0037] To convey the second document G2 in parallel, when the
registration sensor 71 turns on (ACT 207), the processing reaches
ACT 212 via ACT 208 and ACT 211. In ACT 212, if the document G2 is
a sheet of an even ordinal number, the processing goes to ACT 250.
In ACT 250, the gate solenoid 83 is turned on and the gate 40 is
thus switched to the direction to direct the second document G2 to
the IN conveying member 27. Then, in ACT 251, the RGT motor 82 and
the intermediate IN motor 86 are turned on to rotate the
registration rollers 14 and the intermediate IN rollers 28. The
intermediate IN rollers 28 are adjusted to the rotation speed of
the registration rollers 14, and the registration rollers 14 and
the intermediate IN rollers 28 are rotated at a uniform velocity.
The second document G2 is directed by the gate 40 and moves to the
IN conveying member 27.
[0038] In ACT 233, the first document G1 continues traveling on the
READ document glass 110a and the scanner 110 continues scanning the
image. The first document G1 is conveyed in the direction of the
paper discharge rollers 53 via the post-scan rollers 51 and the
pre-discharge rollers 52.
[0039] When the value which the pre-discharge piezoelectric sensor
115 detected is more than a threshold value, it is determined that
a jam exists (ACT 234). When the pre-discharge piezoelectric sensor
115 detected is below a threshold value, the processing goes to ACT
235. When the pre-discharge piezoelectric sensor 115 detects
pressure for more than a predetermined time, it is determined that
a jam exists (ACT 235). When the pre-discharge piezoelectric sensor
115 does not detect pressure for more than a predetermined time,
the processing goes to ACT 236.
[0040] When the first document G1 turns on the paper discharge
sensor 78 (ACT 236), the paper discharge motor 88 is driven to
rotate the paper discharge rollers 53. In the case of double-side
scan (Yes in ACT 238), the processing goes to ACT 239. In ACT 239,
an image on the back side of the first document G1 conveyed in the
paper discharge direction is scanned by the CIS 60. When a
predetermined time passes (ACT 240) after the paper discharge
sensor 78 is turned on, image scanning on the face side of the
first document G1 by the scanner 110 is finished (ACT 241). After
the rear end of the document is passed through the rollers 51, the
READ motor 87 and the intermediate OUT motor 84 are turned off (ACT
242).
[0041] In parallel, when the value which the gate piezoelectric
sensor 111 and the intermediate IN path piezoelectric sensor 113
detected is more than a threshold value, it is determined that a
jam exists (ACT 252). When the value which the gate piezoelectric
sensor 111 and the intermediate IN path piezoelectric sensor 113
detected is below a threshold value, the processing goes to ACT
253. When the gate piezoelectric sensor 111 and the intermediate IN
path piezoelectric sensor 113 detects pressure for more than a
predetermined time, it is determined that a jam exists (ACT 253).
When the gate piezoelectric sensor 111 and the intermediate IN path
piezoelectric sensor 113 do not detect pressure for more than a
predetermined time, the processing goes to ACT 254.
[0042] With respect to the second document G2, when the paper
timing sensor IN 73 is turned on in ACT 254, the RGT motor 82 and
the intermediate IN motor 86 are driven by a predetermined number
of pulses and then stopped (ACT 256). The second document G2 is
stopped before the pre-scan rollers 50 in the IN conveying member
27. If the paper timing sensor IN 73 does not turn on even after a
predetermined time passes in ACT 255, it is determined that the
document G1 causes a jam. After a conveying request signal for the
second document G2 is received from the body control unit 121 in
ACT 257, the processing goes to ACT 258.
[0043] When a predetermined time passes after the forward end of
the preceding document G (the first document G1) turns on the
pre-scan sensor 76 in ACT 258, the processing goes to ACT 259. In
ACT 259, the READ motor 87 and the intermediate IN motor 86 are
turned on and the intermediate IN rollers 28, the pre-scan rollers
50, the post-scan rollers 51 and the paper discharge rollers 52 are
rotated at a speed according to an instruction from the body
control unit 121. The point in time when the rear end of the
preceding document G (the first document G1) passes the pre-scan
rollers 50 and the point in time when the forward end of the second
document G2 starts the conveying by the pre-scan rollers 50 are
caused to coincide with each other. The second document G2 is
conveyed to the READ document glass 110a in the state where the
distance between the rear end of the preceding document G (the
first document G1) and the forward end of the second document G2 is
minimized and approaches 0 mm.
[0044] To realize the state where the distance between the rear end
of the preceding document G (the first document G1) and the forward
end of the second document G2 approaches 0 mm, for example, the
distance from the paper timing sensor OUT 72 to the pre-scan
rollers 50 and the distance from the paper timing sensor IN 73 to
the pre-scan rollers 50 are set to be equal. After the paper timing
sensor IN 73 is turned on, the second document G2 waits at a
position advanced by a predetermined distance. When the rear end of
the preceding document G (the first document G1) is passed through
the paper timing sensor OUT 72 and advances by the predetermined
distance, the READ motor 87 and the intermediate IN motor 86 are
turned on to convey the second document G2 in the direction of the
READ document glass 110a. Thus, the distance between the rear end
of the first document G1 and the forward end of the second document
G2 can be made close to 0 mm.
[0045] Alternatively, the timing of conveying the preceding
document G1 (the first document G1) and the second document G2 can
be adjusted in advance in accordance with the result of detection
by the paper timing sensor OUT 72 and the result of detection by
the paper timing sensor IN 73, thus realizing the state where the
distance between the preceding document G (the first document G1)
and the second document 82 is close to 0 mm.
[0046] The second document G2 conveyed to the READ document glass
110a after the preceding document G (the first document G1) in ACT
259 is conveyed by a predetermined distance (ACT 232) and then
image scanning on the face side by the scanner 110 is started (ACT
233). In parallel, when the rear end of the second document G2 is
passed through the registration sensor 71 and the registration
sensor 71 changes from on to off, supply of the document G3 as the
third sheet (the third document G3) is started. The first document
G1 is discharged in the direction of the paper discharge tray 56 by
the paper discharge rollers 53. The second document G2 travels on
the READ document glass 110a. The third sheet of the third document
G3 runs into the registration rollers 14 and its forward end
position aligned. And then the third document G3 stops.
[0047] To convey the third sheet of the document G3 in parallel, as
the registration sensor 71 turns on (ACT 207), the processing
reaches ACT 212 via ACT 208 and ACT 211. In ACT 212, if the third
document G3 is a sheet of an odd ordinal number, the processing
goes to ACT 214. In ACT 208, the gate solenoid 83 is turned off and
the gate 40 is switched in the direction of dividing the third
document G3 to the OUT conveying member 26. In ACT 214, the
registration rollers 14 and the intermediate OUT rollers 18 are
rotated to convey the third document G3 to the OUT conveying member
26. The first document G1 is set on the paper discharge tray 56.
The second document G2 travels on the READ document glass 110a and
turns on the paper discharge sensor 78. The third document G3 stops
before the pre-scan rollers 50 in the OUT conveying member 26.
After that, the third document G3 is conveyed to the READ document
glass 110a in the state where the distance from the rear end of the
preceding document G (the second document G2) is reduced and
approaches 0 mm.
[0048] When the document G is not the final document, ACTs 214 to
222 (conveying of the document G by the OUT conveying member 26)
and ACTs 250 to 259 (conveying of the document G by the IN
conveying member 27) are alternately repeated and the documents are
continuously conveyed in the state where the distance between the
preceding document and the following document is close to 0 mm (ACT
260). When the document G is the final document and the paper
discharge sensor 78 turns off (ACT 261), the final document is
conveyed by a predetermined distance by the paper discharge rollers
53 (ACT 262). All the motors and solenoids are turned off (ACT
263). Then, conveying of the documents by the ADF 10 is
completed.
[0049] According to this embodiment, in the case of continuously
scanning the documents G, the two conveying members are used, that
is, the OUT conveying member 26 and the IN conveying member 27.
While the preceding first document G1 is conveyed by using one
conveying member, the next second document G2 is caused to stand by
in the other conveying member. The time when the preceding first
document G1 passes through the scanner 110 and the time when the
next second document G2 is conveyed to the scanner 110 are caused
to coincide with each other. Thus, the documents G are continuously
conveyed in the state where the distance between the preceding
first document G1 and the next second document G2 is close to 0
mm.
[0050] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the inventions. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions.
[0051] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the inventions. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions.
* * * * *